ETSI TS 103 738 V1.3.1 (2018-10)

Speech and multimedia Transmission Quality (STQ); Transmission requirements for narrowband wireless terminals (handsfree) from a QoS perspective as perceived by the user

RTS/STQ-272-2

General Information

• Status: Published
• Publication Date: 17-Oct-2018
• Technical Committee: STQ - Speech and multimedia Transmission Quality
• Current Stage: 12 - Completion
• Due Date: 18-Oct-2018
• Completion Date: 18-Oct-2018

Standards Content (Sample)

TECHNICAL SPECIFICATION
Speech and multimedia Transmission Quality (STQ);
Transmission requirements for
narrowband wireless terminals (handsfree)
from a QoS perspective as perceived by the user

2 ETSI TS 103 738 V1.3.1 (2018-10)

Reference
RTS/STQ-272-2
Keywords
speech, terminal
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3 ETSI TS 103 738 V1.3.1 (2018-10)
Contents
Intellectual Property Rights . 5
Foreword . 5
Modal verbs terminology . 5
Introduction . 5
1 Scope . 6
2 References . 6
2.1 Normative references . 6
2.2 Informative references . 7
3 Definitions of terms and abbreviations. 8
3.1 Terms . 8
3.2 Abbreviations . 9
4 Configurations and interfaces . 10
4.0 Introduction . 10
4.1 Access networks . 10
4.2 Additional (radio) links between the terminal and external electroacoustical devices . 10
5 Test Configurations . 10
5.1 Set-up interface . 10
5.2 Set-up for terminals . 11
5.2.0 General . 11
5.2.1 Handheld terminal . 11
5.2.2 Vehicle mounted hands-free . 11
5.2.3 Desktop hands-free terminal . 11
5.2.4 Additional test setup for hands-free function with softphone . 12
5.2.4.0 General . 12
5.2.4.1 Softphone including speakers and microphone . 13
5.2.4.2 Softphone with separate speakers . 14
5.2.5 Test setup for variable echo path . 15
5.3 Acoustical environment . 15
5.4 Test signals . 16
5.5 Calibration and test signal level . 16
5.5.1 Send . 16
5.5.2 Receive . 17
5.5.3 Setup of background noise simulation . 17
5.6 Environmental conditions for tests . 18
5.7 Accuracy of test equipment . 18
5.8 Power feeding conditions . 19
5.9 Influence of terminal delay on measurements . 19
6 Codec independent Requirements and associated Measurement Methodologies . 19
6.1 Send and receive frequency response . 19
6.1.1 Send frequency response . 19
6.1.2 Receive frequency response . 20
6.1.2.1 Handheld terminal . 20
6.1.2.2 Void. 22
6.1.2.3 Softphone (computer-based terminals) . 22
6.1.2.4 Desktop Terminal . 22
6.2 Send and receive loudness ratings . 23
6.2.1 Send Loudness Ratings . 23
6.2.2 Microphone (Mic) mute . 23
6.2.3 Receive Loudness Ratings . 23
6.3 Send and receive noise . 24
6.3.1 Send Noise . 24
6.3.2 Receive Noise . 25
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4 ETSI TS 103 738 V1.3.1 (2018-10)
6.4 Send and receive distortion . 26
6.4.0 General . 26
6.4.1 Send distortion . 26
6.4.2 Receive distortion . 26
6.5 Terminal Coupling Loss weighted (TCLw) . 27
6.6 Stability Loss (or similar parameters) . 27
6.7 Double talk performance . 28
6.7.0 General . 28
6.7.1 Attenuation Range in Send Direction during Double Talk A . 28
H,S,dt
6.7.2 Attenuation Range in Receive Direction during Double Talk A . 29
H,R,dt
6.7.3 Detection of echo components during double Talk . 30
6.7.4 Minimum activation level and sensitivity of double talk detection . 31
6.8 Switching parameters . 32
6.8.0 Introduction. 32
6.8.1 Activation in Send Direction . 32
6.8.2 Minimum activation level and sensitivity in Receive direction . 32
6.8.3 Automatic level control . 33
6.8.4 Silence Suppression and Comfort Noise Generation . 33
6.9 Background noise performance . 33
6.9.1 Performance in send direction in the presence of background noise . 33
6.9.2 Speech Quality in the Presence of Background Noise . 34
6.9.3 Quality of Background Noise Transmission (with Far End Speech) . 35
6.10 Quality of echo cancellation . 35
6.10.1 Temporal echo effects . 35
6.10.2 Spectral Echo Attenuation . 36
6.10.3 Occurrence of Artefacts . 36
6.10.4 Variable echo path . 37
6.11 Send and receive delay or round trip delay . 37
6.12 Void . 39
7 Codec dependent requirements and associated Measurement Methodologies . 39
7.1 Speech Coders . 39
7.2 Void. . 39
7.3 Objective listening speech quality . 39
7.3.0 Introduction. 39
7.3.1 Objective listening speech quality MOS-LQO in send direction . 40
7.3.2 Objective listening quality MOS-LQO in receive direction . 40
7.3.2.1 Jitter- and Error-Free Condition . 40
7.3.2.2 Packet Impairments . 41
Annex A (informative): Bibliography . 44
History . 45

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5 ETSI TS 103 738 V1.3.1 (2018-10)
Intellectual Property Rights
Essential patents
IPRs essential or potentially essential to normative deliverables may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (https://ipr.etsi.org/).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Trademarks
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ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no
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Foreword
This Technical Specification (TS) has been produced by ETSI Technical Committee Speech and multimedia
Transmission Quality (STQ).
Modal verbs terminology
In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and
"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of
provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
Introduction
The present document covers wireless speech terminals. It aims to enhance the interoperability and end-to-end quality
with all other types of terminals.
The advanced signal processing of terminals is targeted to speech signals. Therefore, wherever possible speech signals
are used for testing in order to achieve mostly realistic test conditions and meaningful results.

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6 ETSI TS 103 738 V1.3.1 (2018-10)
1 Scope
The present document provides speech transmission performance requirements for wireless terminals; it addresses all
types of wireless terminals, including softphones. This part addresses handsfree function of narrowband wireless
terminals.
In contrast to other standards which define minimum performance requirements it is the intention of the present
document to specify terminal equipment requirements which enable manufacturers and service providers to enable good
quality end-to-end speech performance as perceived by the user, whatever be the radio link (terminals may implement
different radio links with the access network). ®
When an additional radio link between the terminal and external electroacoustical devices is used (e.g. Bluetooth link),
the standard will address the overall quality.
In the present document, objective measurement methodologies and requirements for wireless speech terminals are
given.
In addition to basic testing procedures, the present document describes advanced testing procedures taking into account
further quality parameters as perceived by the user.
The requirements available in the present document will ensure a high compatibility across access networks with all
types of terminals.
It is the aim to optimize the listening and talking quality, conversational performance, as well as the use in noisy
environment. Related requirements and test methods will be defined in the present document.
For all the functions, the standard will consider the limitations in audio performance due to different form factors
(e.g. size, shape).
Terminals which are not intended to be connected to public networks are outside the scope of the present document.
2 References
2.1 Normative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
https://docbox.etsi.org/Reference/.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are necessary for the application of the present document.
[1] ETSI TS 126 171 (V6.0.0): "Digital cellular telecommunications system (Phase 2+); Universal
Mobile Telecommunications System (UMTS); AMR speech codec, wideband; General description
(3GPP TS 26.171 version 6.0.0 Release 6)".
[2] Recommendation ITU-T G.122: "Influence of national systems on stability and talker echo in
international connections".
[3] Void.
[4] Recommendation ITU-T G.711: "Pulse code modulation (PCM) of voice frequencies".
[5] Recommendation ITU-T G.726: "40, 32, 24, 16 kbit/s Adaptive Differential Pulse Code
Modulation (ADPCM)".
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7 ETSI TS 103 738 V1.3.1 (2018-10)
[6] Recommendation ITU-T G.729: "Coding of speech at 8 kbit/s using conjugate-structure
algebraic-code-excited linear prediction (CS-ACELP)".
[7] Recommendation ITU-T G.729.1: "G.729 based embedded variable bit-rate coder: An 8-32 kbit/s
scalable wideband coder bitstream interoperable with G.729".
[8] Void.
[9] Recommendation ITU-T P.56: "Objective measurement of active speech level".
[10] Recommendation ITU-T P.58: "Head and torso simulator for telephonometry".
[11] Recommendation ITU-T P.79: "Calculation of loudness ratings for telephone sets".
[12] Recommendation ITU-T P.340: "Transmission characteristics and speech quality parameters of
hands-free terminals".
[13] Recommendation ITU-T P.342: "Transmission characteristics for narrow-band digital
loudspeaking and hands-free telephony terminals".
[14] Recommendation ITU-T P.501: "Test signals for use in telephonometry".
[15] Recommendation ITU-T P.502: "Objective test methods for speech communication systems using
complex test signals".
[16] Recommendation ITU-T P.581: "Use of head and torso simulator (HATS) for hands-free terminal
testing".
[17] Recommendation ITU-T O.41: "Psophometer for use on telephone-type circuits".
[18] IEC 61260-1: "Electroacoustics - Octave-band and fractional-octave-band filters -
Part 1: Specifications".
[19] ETSI TS 146 010: "Digital cellular telecommunications system (Phase 2+); Full-rate speech;
Transcoding (3GPP TS 46.010 Release 9)".
[20] ETSI TS 146 060: "Digital cellular telecommunications system (Phase 2+); Enhanced Full Rate
(EFR) speech transcoding (3GPP TS 46.060 Release 9)".
[21] ETSI TS 103 106 (03-2013) (V1.2.1): "Speech and multimedia Transmission Quality (STQ);
Speech quality performance in the presence of background noise: Background noise transmission
for mobile terminals-objective test methods".
[22] Recommendation ITU-T P.863: "Perceptual objective listening quality prediction".
[23] Recommendation ITU-T P.863.1: "Application guide for Recommendation ITU-T P.863".
[24] ETSI TS 126 441 (V12.0.0): "Universal Mobile Telecommunications System (UMTS); LTE; EVS
Codec General Overview (3GPP TS 26.441 version 12.0.0 Release 12)".
[25] ETSI TS 103 224: "Speech and multimedia Transmission Quality (STQ); A sound field
reproduction method for terminal testing including a background noise database".
2.2 Informative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are not necessary for the application of the present document but they assist the
user with regard to a particular subject area.
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8 ETSI TS 103 738 V1.3.1 (2018-10)
[i.1] Void.
[i.2] Recommendation ITU-T P.1100: "Narrowband hands-free communication in motor vehicles".
[i.3] IEC 61672 (Edition 1.0): "Electroacoustics - Sound level meters".
[i.4] Void.
[i.5] Void.
[i.6] ETSI EG 201 377-1: "Speech and multimedia Transmission Quality (STQ); Specification and
measurement of speech transmission quality; Part 1: Introduction to objective comparison
measurement methods for one-way speech quality across networks".
[i.7] Recommendation ITU-T P.1010: "Fundamental voice transmission objectives for VoIP terminals
and gateways".
3 Definitions of terms and abbreviations
3.1 Terms
For the purposes of the present document, the following terms apply:
artificial ear: device for the calibration of earphones incorporating an acoustic coupler and a calibrated microphone for
the measurement of the sound pressure and having an overall acoustic impedance similar to that of the median adult
human ear over a given frequency band
codec: combination of an analogue-to-digital encoder and a digital-to-analogue decoder operating in opposite directions
of transmission in the same equipment
ear-Drum Reference Point (DRP): point located at the end of the ear canal, corresponding to the ear-drum position
freefield equalization: artificial head equalized flat for frontal sound incidence in anechoic conditions
group audio terminal: handsfree telephony terminal primarily designed for use by several users which will not be
equipped with a handset.
handsfree telephony terminal: telephony terminal using a loudspeaker associated with an amplifier as a telephone
receiver and which can be used without a handset
HATS Hands-Free Reference Point (HATS HFRP): reference point "n" from Recommendation ITU-T P.58 [10]: "n"
is one of the points numbered from 11 to 17 and defined in table 6a of Recommendation ITU-T P.58 [10] (coordinates
of far field front point)
NOTE: The HATS HFRP depends on the location(s) of the microphones of the terminal under test: the
appropriate axis lip-ring/HATS HFRP is to be as close as possible to the axis lip-ring/HFT microphone
under test.
Head And Torso Simulator (HATS) for telephonometry: manikin extending downward from the top of the head to
the waist, designed to simulate the sound pick-up characteristics and the acoustic diffraction produced by a median
human adult and to reproduce the acoustic field generated by the human mouth
loudspeaking function: function of a handset telephone using an external loudspeaker associated with an amplifier as a
telephone receiver
Mouth Reference Point (MRP): point located on axis and 25 mm in front of the lip plane of a mouth simulator
nominal setting of the volume control: volume control setting which yields the RLR value closest to the nominal RLR
NOTE: If no user operable volume control is available, this should be noted in the test report.
softphone: speech communication system based upon a computer
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9 ETSI TS 103 738 V1.3.1 (2018-10)
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
a.c. alternative current
A attenuation range in send direction during double talk
H,S,dt
AM-FM Amplitude Modulation Frequency Modulation
AMR Adaptive Multi-Rate codec
CDMA Code Division Multiple Access
CS Composite Source
CSS Composite Source Signal
DECT Digital Enhanced Cordless Telecommunications
DFT Discrete Fourrier Transform
DRP Drum Reference Point
DUT Device Under Test
EC Echo Cancellation
EFR Enhanced Full Rate
EL Echo loss
EVS-NB Enhanced Voice Services - Narrowband
FFT Fast Fourier Transform
G-MOS-LQOn Overall transmission quality narrowband
GSM Global System for Mobile communication
HATS Head And Torso Simulator
HF Handsfree
HFRP Handsfree Reference Point
HFT Handsfree Telephone
IEC International Electrotechnical Commission
ITU-T International Telecommunication Union - Telecommunication standardization sector
LE Earcap Leakage/Coupling Loss
LQO Listening Quality Objective
LTE Long Term Evolution (3GPP)
MOS Mean Opinion Score
MRP Mouth Reference Point
NB Narrow Band
NLP Non Linear Processing
N-MOS-LQOn Transmission quality of the background noise narrowband
PDA Personal Data Analyser
PLC Packet Loss Concealment
PMRP Sound Pressure at MRP
PN Pseudo random Noise
POI Point Of Interconnect
QoS Quality of Service
RF Radio Frequency
RLR max Receive Loudness Rating corresponding to the maximum setting of the volume control
RLR min Receive Loudness Rating corresponding to the minimum setting of the volume control
RLR Receive Loudness Rating
RMS Root Mean Square
SLR Send Loudness Rating
S-MOS-LQOn Transmission quality of the speech narrowband
TCL Terminal Coupling Loss (weighted)
w
TELR Talker Echo Loudness Rating
dt
TOSQA Telecommunication Objective Speech Quality Assessment
UE User Equipment
UMTS Universal Mobil Telecommunications System
VAD Voice Activity Detector
VoLTE Voice over LTE
WIFI Wireless Fidelity
WIMAX™ Worldwide Interoperability for Microwave ACCess
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4 Configurations and interfaces
4.0 Introduction
The present document is intended to be applicable for different wireless access networks and for additional radio links.
4.1 Access networks
The present document applies to any wireless terminal whatever the access network, e.g. GSM, UMTS, VoLTE, DECT, ®
Bluetooth , WIFI, WIMAX™, CDMA, etc.
4.2 Additional (radio) links between the terminal and external
electroacoustical devices
The present document also applies when an additional radio link exists between the wireless terminal and external ®
electro acoustic devices, e.g. Bluetooth .
5 Test Configurations
5.1 Set-up interface
The generic schematic as defined in figure 5.1-1 is applicable to any wireless link.
POI
air interface
(electrical interface)
Hands-free
Speech Speech 4-wire
signal RF-Interface RF-Interface
Transcoder Transcoder Tx
processing
mobile phone
System Simulator
Hands-Free Terminal
~
~
Test System
NOTE: The "whole" terminal includes all the components from "RF interface" to the transducers and may include
an additional (radio) link. The air interface considered in figure 5.1-1 is not the additional radio link.

Figure 5.1-1: Set-up interface
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11 ETSI TS 103 738 V1.3.1 (2018-10)
5.2 Set-up for terminals
5.2.0 General
For electroacoustical testing, HATS as described in Recommendation ITU-T P.58 [10] shall be used.
The preferred way of testing a terminal is to connect it to a network simulator with exact defined settings and access
points. The test sequences are fed in either electrically, using a reference codec or using the direct signal processing
approach or acoustically using ITU-T specified devices.
When a coder with variable bit rate is used for testing terminal electroacoustical parameters, the bit rate giving the best
characteristics or the most commonly used should be selected, e.g.:
• AMR-NB (ETSI TS 126 171 [1]): 12,2 kbit/s
• Recommendation ITU-T G.729.1 [7]: 32 kbit/s
5.2.1 Handheld terminal
HATS measurement equipment shall be configured to the handheld hands-free UE according to figure 5.2-1. The HATS
should be positioned so that the HATS Reference Point is at a distance d from the centre point of the visual display of
HF
the Mobile Station. The distance d is specified by the manufacturer. A vertical angle θ may be specified by the
HF HF
manufacturer. In case it is not specified the distance d shall be 42 cm and θ shall be 0.
HF HF
NOTE: The nominal distance of 42 cm corresponds to lip plane-HATS reference point distance (12 cm) with an
additional 30 cm giving a realistic figure as a reference usage of handheld terminals.

Figure 5.2-1: Configuration of handheld hands-free UE relative to the HATS
5.2.2 Vehicle mounted hands-free
Test arrangement, test methods and performance requirements are according to Recommendation ITU-T P.1100 [i.2].
Figure 5.2.2-1: Void.
5.2.3 Desktop hands-free terminal
Definition of hands-free terminals and setup for desktop hands-free terminals are based on in Recommendation
ITU-T P.581 [16].
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12 ETSI TS 103 738 V1.3.1 (2018-10)

Figure 5.2.3-1: Position for test of desktop hands-free terminal side view

Figure 5.2.3-2: Position for test of desktop hands-free terminal top sight
5.2.4 Additional test setup for hands-free function with softphone
5.2.4.0 General
Two types of softphones are to be considered:
• Type 1 is to be used as a desktop type (e.g. notebook).
• Type 2 is to be used as a handheld type (e.g. PDA).
When manufacturer gives conditions of use, they will apply for test. If no other requirement is given by manufacturer
softphone will be positioned according the following conditions.
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13 ETSI TS 103 738 V1.3.1 (2018-10)
5.2.4.1 Softphone including speakers and microphone

Figure 5.2.4.1-1: Configuration of softphone relative to the HATS side view

Figure 5.2.4.1-2: Configuration of softphone relative to the HATS-top sight
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14 ETSI TS 103 738 V1.3.1 (2018-10)
5.2.4.2 Softphone with separate speakers
When separate loudspeakers are used, system will be positioned as in figure 5.2.4.2-1.
80 cm
Hands free softphone
Loudspeaker Loudspeaker
Test table
40 cm
40 cm
20 cm
40 cm
40 cm
HATS
Figure 5.2.4.2-2: Configuration of softphone using external speakers relative to the HATS-top sight
When external microphone and speakers are used, system will be positioned as in figure 5.2.4.2-3.

Figure 5.2.4.2-3: Configuration of softphone using
external speakers and microphone relative to the HATS-top sight
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15 ETSI TS 103 738 V1.3.1 (2018-10)
5.2.5 Test setup for variable echo path
Test setup for desktop hands-free terminals: A notebook is positioned at least 20 cm in front of the device (or devices)
with the transducers, as shown in figure 5.2.5-1. The notebook lid is moved during the measurement.
> 20cm
Figure 5.2.5-1: Positioning of DUT
Test setup for softphone: The test setup is described in clause 6.2. The notebook lid is moved during the measurement,
as shown in figure 5.2.5-2. This setup is valid for all combinations of notebook with or without external speakers or
microphone:
Figure 5.2.5-2: Positioning of DUT
Test setup for other hands-free devices is for further study.
5.3 Acoustical environment
In general, different acoustical environments have to be taken into account: either room noise and background noise are
an inherent part of the test environment or room noise and background noise shall be eliminated to such an extent that
their influence on the test results can be neglected.
Unless stated otherwise measurements shall be conducted under quiet and "anechoic" conditions.
Considering this, the test laboratory, in the case where its test room does not conform to anechoic conditions as given in
Recommendation ITU-T P.342 [13], has to present difference in results for measurements due to its test room. In case
where an anechoic room is not available the test room has to be an acoustically treated room with few reflections and a
low noise level.
In cases where real or simulated background noise is used as part of the testing environment, the original background
noise shall not be noticeably influenced by the acoustical properties of the room.
In all cases where the performance of acoustic echo cancellers shall be tested, a realistic room, which represents the
typical user environment for the terminal shall be used.
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5.4 Test signals
Due to the coding of the speech signals, care should be taken when using sinusoidal test signals for some wireless
terminals/networks (e.g. GSM/3G), appropriate test signals (general description) are defined in Recommendation
ITU-T P.501 [14].
Unless stated otherwise the test signal to be used for the measurements shall be the British-English single talk sequence
described in clause 7.3.2 of Recommendation ITU-T P.501 [14]. More information can be found in the test procedures
described below.
For testing the narrowband telephony service provided by a terminal the test signal used shall be band limited between
100 Hz and 4 kHz with a bandpass filter providing a minimum of 24 dB/Oct. filter roll off, when feeding into the
receive direction.
Unless specified otherwise, the test signal levels are referred to the average level of the (band limited in receive
direction) test signal, averaged over the complete test sequence, unless specified otherwise.
Unless specified otherwise, the test signal level shall be -4,7 dBPa at the MRP, calibrated at the various positions as
defined in clause 5.5.1.
Unless specified otherwise, the applied test signal level at the digital input shall be -16 dBm0.
5.5 Calibration and test signal level
5.5.1 Send
Unless specified otherwise, the test signal level shall be -4,7 dBPa at the MRP.
The various steps for calibration of the artificial mouth are described in Recommendation ITU-T P.581 [16].
The test setup shall be in conformance with, figure 5.5.1-1 but depending on the type of terminal, the appropriate
distance and level will be used. When using this calibration method, send sensitivity shall be calculated as follows:
S = 20logV − 20logP + Corr − Dcorr
mJ s MRP
where:
• Vs is the measured voltage across the appropriate termination (unless stated otherwise, a 600 Ω termination).
• PMRP is the applied sound pressure at the MRP.
• Corr is 20 log (PMRP/PHFRP) of the used artificial mouth.
The value of Corr is the value required to calibrate the artificial mouth to the exact value of Dcorr
(e.g. 24,0 dB for 50 cm distance).
• Dcorr is the correction to achieve the target sound pressure level at the intended distance (see below).
NOTE: Reason for this procedure of calibration in two steps is to take into account the different variation of
signal with distance by using different implementations of HATS.

Figure 5.5.1-1: Calibration at HFRP for HATS
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17 ETSI TS 103 738 V1.3.1 (2018-10)
The distance used for level calibration corresponds to the following values:
Desktop terminal: 50 cm and level to adjust -28,7 dBPa, Dcorr = 24 dB
Handheld terminal: 30 cm with -24,3 dBPa, Dcorr = 19,6 dB
Softphone: 36 cm with -25,8 dBPa, Dcorr = 21,1 dB
5.5.2 Receive
Unless specified otherwise, the applied test signal level at the digital input shall be -16 dBm0.
All measurement values produced by HATS are intended to be free-field equalized according Recommendation
ITU-T P.581 [16].
5.5.3 Setup of background noise simulation
A setup for simulating realistic background noises in a lab-type environment is described in ETSI TS 103 224 [25].
ETSI TS 103 224 [25] contains a description of the recording arrangement for realistic background noises, a description
of the setup for a loudspeaker arrangement suitable to simulate a background noise field in a lab-type environment and a
database of realistic background noises, which can be used for testing the terminal performance with a variety of
different background noises.
The principle loudspeaker setup for the simulation arrangement is shown in figure 5.5.3-1.

Figure 5.5.3-1: Loudspeaker arrangement for background noise simulation
The equalization and calibration procedure for the setup is described in detail in ETSI TS 103 224 [25].
If not stated otherwise this setup is used in all measurements where background noise simulation is required.
The following noises of ETSI TS 103 224 [25] shall be used.
ETSI
18 ETSI TS 103 738 V1.3.1 (2018-10)
Table 5.5.3-1: Noises used for background noise simulation
Name Description Length Handsfree Levels
Full-size car HATS and microphone array at 30 s
130 km/h co-drivers position 1: 69,5 dB 2: 68,6 dB
(FullSizeCar_130) 3: 68,6 dB 4: 68,7 dB
5: 68,8 dB 6: 68,8 dB
7: 69,2 dB 8: 69,7 dB
Cafeteria (Cafeteria) HATS and microphone array 30 s
inside a cafeteria 1: 69,0 dB 2: 69,7 dB
3: 69,6 dB 4: 69,8 dB
5: 69,5 dB 6: 69,5 dB
7: 69,7 dB 8: 70,0 dB
Roadnoise HATS and microphone array 30 s
(Roadnoise) standing outside near a road 1: 69,9 dB 2: 70,7 dB
3: 70,9 dB 4: 71,0 dB
5: 70,8 dB 6: 70,8 dB
7: 70,9 dB 8: 71,0 dB
Pub Noise (Pub) HATS and microphone array in a 30 s
Pub 1: 75,2 dB 2: 75,1 dB
3: 74,9 dB 4: 75,1 dB
5: 74,8 dB 6: 74,8 dB
7: 74,8 dB 8: 75,0 dB
Airport departure HATS and microphone array in 30 s
an airport gate area 1: 77,2 dB 2: 77,4 dB
3: 77,6 dB 4: 77,7 dB
5: 78,1 dB 6: 77,9 dB
7: 77,8 dB 8: 77,9 dB
5.6 Environmental conditions for tests
The following conditions shall apply for the testing environment:
a) Ambient temperature: 15 °C to 35 °C (inclusive);
b) Relative humidity: 5 % to 85 %;
c) Air pressure: 86 kPa to 106 kPa (860 mbar to 1 060 mbar).
5.7 Accuracy of test equipment
Unless specified otherwise, the accuracy of measurements made by test equipment shall be better than:
Table 5.7-1: Accuracy of measurements
Item Accuracy
Electrical Signal Level
±0,2 dB for levels ≥ -50 dBV
Electrical Signal Level ±0,4 dB for levels < -50 dBV
Sound pressure
±0,7 dB
Frequency
±0,2 %
Time ±0,2 %
Measured maximum frequency
20 kHz
Clock Accuracy
< 2 ppm
NOTE: The measured maximum frequency is due to P.58 limitations.

ETSI
19 ETSI TS 103 738 V1.3.1 (2018-10)
Unless specified otherwise, the accuracy of the signals generated by the test equipment shall be better than:
Table 5.7-2: Accuracy of generated signals
Quantity Accuracy
Sound pressure level at MRP ±3 dB for 100 Hz to 200 Hz
±1 dB for 200 Hz to 4 kHz
±3 dB for 4 kHz to 8 kHz
Electrical excitation levels ±0,4 dB across the whole frequency range
Frequency generation ±2 % (see note)
Time ±0,2 %
NOTE: This tolerance may be used to avoid measurements at critical frequencies, e.g. those due to
sampling and coding operations within the terminal under test.

The measurements results shall be corrected for the measured deviations from the nominal level.
The sound level measurement equipment shall conform to IEC 61672 [i.3] Type 1.
5.8 Power feeding conditions
For terminal equipment which is directly powered from the mains supply, all tests shall be carried out within ±5 % of
the rated voltage of that supply. If the equipment is powered by other means and those means are not supplied as part of
the apparatus, all tests shall be carried out within the power supply limit declared by the supplier. If the power supply is
a.c., the test shall be conducted within ±4 % of the rated frequency.
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